The present invention relates to a support structure for an ordinary shelter or tent, and particularly to a support structure for a collapsible shelter.
Nowadays, shelters are extensively used in recreation, amusement and touring. A shelter usually comprises a canvas covering and a support structure, which in turn is constituted of legs, beams and sometimes also top bars. The construction of said shelter is designed such that it can be dismantled and assembled readily. The various members of the support structure and canvas covering are assembled whenever it is to be used, and after use, all of them are dismantled for the ease of portability. But it is rather tedious to reassemble the entire support structure and canvas covering every time when it is to be used. A shelter of collapsible construction such as disclosed in U.S. Pat. No. 4,607,656 could be conveniently collapsed, stored and transported, but the canvas covering in this case cannot be fully spread out due to lack of beams so as to affect its effectiveness in use.
The present invention aims to provide a support structure for a collapsible shelter which is easily and quickly spread and collapsed with no need to dismantle and assemble it every time when it is to be used.
To achieve this aim, the support structure for a collapsible shelter of the present utility model comprises legs and upper beams etc., at least three in number for each of them, with the top ends of the legs being connected respectively with the upper beams. Wherein each said upper beam is composed of two separate component rods jointed together by a hinge to freely swing with respect to each other. The two ends of the upper beam are connected to the top end of the adjacent legs respectively by freely swinging hinges. Each said leg has a sliding part thereon. There is an upper stay bar or upward stay bar between the sliding part and the component rods of the upper beam connected to the leg. Both end connections of the upper stay bar are freely swinging hinges. Said leg has also a stop means thereon to limit motion of the sliding part during spreading.
In addition, said support structure for a collapsible shelter has at least three lower beams. Each said lower beam is composed of two separate component rods jointed together by a hinge to freely swing with respect to each other. The two external ends of each said lower beam are connected to sliding parts of adjacent legs through freely swing hinges respectively. There is a lower stay bar or downward stay bar respectively between the top of the leg and the component rods of the lower beam connected to the leg. Both end connections of the lower stay bar are freely swinging hinges.
Moreover, said support structure for a collapsible shelter has at least three top bars, each of which is in turn composed of two separate component bars jointed together by hinge to freely swing with respect to each other. One of the external ends of each said top bar is jointed to the top end of a leg through a freely swinging hinge, while the other end of all top bars are jointed together by a freely swinging hinge. There is a top stay bar respectively between the sliding part on the leg, and the component bars of the top bar connected to the leg. Both end connections of the top stay bar are freely swinging hinges.
With the above structure, after a canvas covering is fixed on the upper beams or top bars of the support structure, a collapsible shelter is formed. While in use, as the sliding parts are sliding upward along the legs, triangles are formed by the upper stay bar, leg and a component rod of upper beam, by lower or downward stay bar, leg and a component rod of lower beam, and also by top stay bar, leg and a component bar of top bar respectively. As the upward motion goes forward, these triangles are transformed continuously due to the relative swinging between them through hinges. The transformation would not be ceased until the two component rods of each upper and lower beam are connected in a straight line, all upper and lower beams outspread straightly and the support structure is erected completely. At this time, the sliding part is locked up by stop means of the leg to prevent collapse of the shelter on account of a downward motion of the sliding part, and the shelter is now completely outspread and ready for use. While the shelter is not used, the stop means is released, and sliding part moves downward along the leg, which result in a series of the following motions: the upper stay bar pulls the adjacent component rod of the upper beam to swing downward; the component rod of the low beam swings upward and pulls the lower stay bar to swing downward; the top stay bar pulls the top bar to swing downward (i.e. a reverse transformation of triangles during the above process of shelter outspreading). Upper beams, lower beams and top bars are folded gradually, and all legs move toward the common center until the support structure and canvas covering are fully collapsed and folded completely. Therefore, collapsible shelter with the present support structure does not need to be assembled and dismantled each time when it is to be used. Said collapsible shelter can be easily and quickly spread out and collapsed, saving both time and manpower. The canvas covering can also be fully outspread due to presence of beams and top bars, thus enhancing sheltering effect.